Pro-Palestinian protesters burned an American flag and clashed with police in Chicago.

As Barack and Michelle Obama addressed delegates at the Democratic National Convention in the city’s United Center, protesters clashed with officers in riot gear.

After the protesters staged an unauthorised rally outside the city’s Israeli consulate, at least two flags were set alight.

Witnesses said one of the flags was the Stars and Stripes and another was an American flag with the star of David.

Around 200 pro-Palestinian protesters – many dressed in black, with their faces covered – attempted to break through a police line, leading to clashes with officers.

At least 72 people were arrested as Chicago officers, equipped with face shields and batons, attempted to restore order.

Police superintendent Larry Snelling said: “We have people who showed up here to commit acts of violence. They wanted chaos.”

A group called Behind Enemy Lines organised the rally, which had not been permitted by the city’s authorities.

Pro-Palestinian leaders representing Monday’s more peaceful march on the Democratic Convention said they were not associated with Tuesday’s rally.

A small group of pro-Israel demonstrators also gathered on Tuesday. Elan Carr, the CEO of the Israeli-American Council, condemned the pro-Palestinian protesters, calling them “fringe crazies” and demanding that US leaders “stand unequivocally with the state of Israel”.